In many roofing applications, for example in large, flat commercial roof decks, the roofing substrate is a concrete, light weight concrete, wood, gypsum, wood fiber or steel roof deck. The roofing membrane is used to seal and protect the roof deck from environmental weather conditions and is placed over insulation boards, which provide insulative qualities. The insulation boards are typically secured to the roofing substrate or roof deck via an adhesive composition. A conventional adhesive composition used to adhere the insulation boards to the roof deck includes polyurethane. The polyurethane adhesives are oftentimes applied directly onto the roof deck, and the insulation boards are then laid onto the roof deck surface. Conventional polyurethane adhesives oftentimes include two separate parts that are mixed by an applicator just prior to being applied onto the surface of the roof deck. The two parts include an isocyanate blend and a polyol blend. Upon mixing, the isocyanate blend reacts or crosslinks with the polyol blend to form the polyurethane adhesive.
The roofing membrane may be made of various materials, such as polymeric materials including EPDM (ethylene propylene diene M-rubber), Mod Bit (Modified Bitumen), TPO (thermoplastic polyolefin), or polyvinyl chloride (PVC). The roofing membrane may be a composite material that includes EPDM or TPO, an example of which is Carlisle's FleeceBACK® EPDM and FleeceBACK® TPO. The roofing membrane is adhered overtop insulation boards or panels using an adhesive composition such as mopping asphalt (typically Type III or Type IV) or other conventional adhesive compositions that includes polyurethanes. There is room in the art for adhesive compositions in roofing applications that exhibit favorable properties, such as sufficient adhesive strength, shelf life, cure time, and tack that also have high renewable carbon content and/or renewable or environmentally favorable polyol and isocyanate content.